For added flair, put in a dash of Pernod and some crushed fennel seeds. Use as a sauce for shellfish, as a spread for canapés, or for finishing béchamel or velouté sauces served with fish.
Dry in a 250┬░F oven for 10 to 20 minutes:
Uncooked or cooked shells from 1 pound shrimp or crayfish or from 1 1 1/2- to 2-pound lobster, well rinsed and drained
Break up the shells as finely as possible with a wooden mallet or rolling pin. Melt in the top of a double boiler over simmering water:
8 tablespoons unsalted butter
Add the shells and simmer gently for 10 minutes; do not let the butter boil. Set aside for 20 minutes to allow the flavors to infuse. Strain through a fine-mesh sieve lined with several layers of cheesecloth into a bowl. Place the bowl in a larger bowl of ice water to cool quickly. Refrigerate and skim off the butter when the mixture is solidified. Discard the liquid.
